CN105262532B - Communication system, communication control method, mobile terminal and relay device - Google Patents

Communication system, communication control method, mobile terminal and relay device Download PDF

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Publication number
CN105262532B
CN105262532B CN201510568498.6A CN201510568498A CN105262532B CN 105262532 B CN105262532 B CN 105262532B CN 201510568498 A CN201510568498 A CN 201510568498A CN 105262532 B CN105262532 B CN 105262532B
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China
Prior art keywords
relaying
mobile terminal
reference signal
communication
base station
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CN105262532A (en
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高野裕昭
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Sony Corp
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Sony Corp
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/155—Ground-based stations
    • H04B7/15557—Selecting relay station operation mode, e.g. between amplify and forward mode, decode and forward mode or FDD - and TDD mode
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
    • H04L5/0051—Allocation of pilot signals, i.e. of signals known to the receiver of dedicated pilots, i.e. pilots destined for a single user or terminal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/155—Ground-based stations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/02—Details
    • H04L12/12—Arrangements for remote connection or disconnection of substations or of equipment thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0203—Power saving arrangements in the radio access network or backbone network of wireless communication networks
    • H04W52/0206—Power saving arrangements in the radio access network or backbone network of wireless communication networks in access points, e.g. base stations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
    • H04W64/003—Locating users or terminals or network equipment for network management purposes, e.g. mobility management locating network equipment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/28—Discontinuous transmission [DTX]; Discontinuous reception [DRX]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W40/00—Communication routing or communication path finding
    • H04W40/02—Communication route or path selection, e.g. power-based or shortest path routing
    • H04W40/22—Communication route or path selection, e.g. power-based or shortest path routing using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/02—Selection of wireless resources by user or terminal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
    • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/04—Large scale networks; Deep hierarchical networks
    • H04W84/042—Public Land Mobile systems, e.g. cellular systems
    • H04W84/047—Public Land Mobile systems, e.g. cellular systems using dedicated repeater stations
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Abstract

The invention relates to a communication system, a communication control method, a mobile terminal and a relay device. A communication system is configured, the communication system including a mobile terminal, one or more relay devices, and a base station communicating with the mobile terminal via any one of the one or more relay devices, wherein the mobile terminal includes a receiving unit that receives a reference signal transmitted from the one or more relay devices, a determining unit that determines a relay device to be used for communication with the base station based on the reference signal received by the receiving unit from the one or more relay devices, and a transmitting unit that transmits information indicating the relay device determined by the determining unit to the base station.

Description

Communication system, communication control method, mobile terminal and relay device
The application is a divisional application of an invention patent application named as 'communication system, communication control method, mobile terminal and relay device' of PCT application PCT/JP2010/059852 with Chinese patent application number of 201080031787.8 and application date of 10/6/2010.
Technical Field
the present invention relates to a communication system, a communication control method, a mobile terminal and a relay device.
Background
In 3GPP (third generation partnership project), a technology for realizing throughput increase at a cell edge with a relay device (relay station) is being actively studied.
Such a relay device receives a signal transmitted from a base station in a downlink, amplifies the signal, and then transmits the amplified signal to a mobile terminal. By performing such relaying, the relay apparatus can increase the signal-to-noise ratio as compared to when transmitting a signal directly from the base station to the mobile terminal. Similarly, in the uplink, the relay device can maintain a high signal-to-noise ratio by forwarding a signal transmitted from the mobile terminal to the base station.
Further, as a relay scheme of the relay device, an Amp-Forward type relay, a Decode-Forward type relay, and the like can be given. The Amp-Forward type relay is a scheme of amplifying and transmitting a reception signal while maintaining the reception signal as an analog signal. According to this Amp-Forward type relay, although the signal-to-noise ratio is not improved, there is an advantage in that it is not necessary to modify the communication protocol. In addition, the relay device has a feedback path between the transmission antenna and the reception antenna, and is designed so that the feedback path does not oscillate.
The Decode-Forward type relay is a scheme of converting a received signal into a digital signal by AD conversion, decoding the digital signal such as error correction, re-encoding the decoded digital signal, converting the digital signal into an analog signal by DA conversion, amplifying the analog signal, and then transmitting the analog signal. According to the Decode-Forward type relay, the signal-to-noise ratio can be improved by using the coding gain. In addition, by storing a digital signal obtained by reception in a memory and then transmitting the digital signal in the next time slot, the relay apparatus can avoid oscillation of a feedback path between the transmitting antenna and the receiving antenna. In addition, the relay device can also avoid the oscillation by changing the frequency instead of the time slot.
Further, since it is assumed that there are a plurality of relay apparatuses existing within a cell provided by a base station, it is effective to implement a power saving mode (sleep mode) in the relay apparatuses from the viewpoint of reducing power consumption. In addition, a power saving mode in LTE (long term evolution) is described in non-patent document 1.
Reference list
Non-patent document
Non-patent document 1 Erik Dahlman, Stefan park Vall et al, "3G Evolution: HSPA and LTE for Mobile Broadband", 2007, p.314.
disclosure of Invention
However, if the relay device according to the power saving mode does not transmit a radio signal, the mobile terminal cannot receive a radio signal from the relay device operating according to the power saving mode, so that it is difficult to appropriately determine the relay device to be used for communication between the base station and the mobile terminal.
Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a new and improved communication system, communication control method, mobile terminal and relay device capable of determining a relay device to be used for communication between a base station and a mobile terminal from among one or more relay devices having a power saving mode.
according to an aspect of the present invention, to achieve the above object, there is provided a communication system including: the mobile terminal includes a receiving unit that receives a reference signal transmitted from the one or more relay devices, a determining unit that determines a relay device to be used for communication with the base station based on the reference signal received by the receiving unit from the one or more relay devices, and a transmitting unit that transmits information indicating the relay device determined by the determining unit to the base station.
The one or more relay devices may each perform transmission of the reference signal in an active mode that allows communication relay between the base station and the mobile terminal, and in a power saving mode that performs intermittent reception.
The base station may include a mode control unit that, when information indicating the relay device is received from the mobile terminal, instructs the relay device to transition to the active mode if the relay device is operating in the power saving mode.
The one or more relay devices may not necessarily transmit the reference signal when operating in the power saving mode but may transmit the reference signal when operating in the active mode, and the base station may include a terminal position acquisition unit that acquires position information of the mobile terminal, a selection unit that selects one of the one or more relay devices based on the position information of the mobile terminal acquired by the terminal position acquisition unit, and a mode control unit that issues an instruction to transition to the active mode in a case where the relay device selected by the selection unit is operating in the power saving mode.
The terminal position acquisition unit may acquire the position information of the mobile terminal according to the arrival direction and the reception intensity of the signal transmitted from the mobile terminal.
The mobile terminal may transmit reception strength information of each signal transmitted from the plurality of base stations to the base station, and the terminal location acquisition unit may acquire the location information of the mobile terminal based on the reception strength information of each of the plurality of base stations received from the mobile terminal.
The plurality of base stations may transmit reception strength information of a signal transmitted by the mobile terminal to the base stations, and the terminal location acquiring unit may acquire the location information of the mobile terminal based on the reception strengths of the signal transmitted by the mobile terminal at the plurality of base stations.
The mobile terminal may transmit the reception intensity information of each signal transmitted from the base station and the one or more relay devices to the base station, and the terminal position obtaining unit may obtain the position information of the mobile terminal based on the reception intensity information received from the mobile terminal.
The mobile terminal may transmit the position information of the mobile terminal estimated using the GPS to the base station, and the terminal position acquisition unit may obtain the position information of the mobile terminal transmitted from the mobile terminal.
According to another aspect of the present invention to achieve the above object, there is provided a communication control method including the steps of: the method includes receiving, with a mobile terminal, a reference signal transmitted from one or more relay devices, determining a relay device to be used for communication with a base station based on the reference signal received from the one or more relay devices, and transmitting information indicating the determined relay device to the base station.
According to another aspect of the present invention to achieve the above object, there is provided a mobile terminal including a receiving unit receiving a reference signal transmitted from one or more relay devices, a determining unit determining a relay device to be used for communication with a base station based on the reference signal received by the receiving unit from the one or more relay devices, and a transmitting unit transmitting information indicating the relay device determined by the determining unit to the base station.
According to another aspect of the present invention, to achieve the above object, there is provided a relay apparatus. The relay device relays communication between a mobile terminal and a base station, the mobile terminal including a receiving unit that receives a reference signal transmitted from one or more relay devices, a determining unit that determines a relay device to be used for communication with the base station based on the reference signal received by the receiving unit from the one or more relay devices, and a transmitting unit that transmits information indicating the relay device determined by the determining unit to the base station.
as described above, according to the present invention, a relay device to be used for communication between a base station and a mobile terminal can be determined from one or more relay devices having a power saving mode.
Drawings
Fig. 1 is an explanatory diagram showing a configuration of a communication system according to an embodiment of the present invention.
Fig. 2 is an explanatory diagram showing each link in the communication system according to the embodiment of the invention.
Fig. 3 is an explanatory diagram showing an exemplary structure of a radio frame used in the communication system according to the embodiment.
Fig. 4 is an explanatory diagram showing an operation mode of a mobile terminal according to LTE.
Fig. 5 is a functional block diagram showing the configuration of the relay apparatus according to the first embodiment.
Fig. 6 is an explanatory diagram showing an operation of the relay apparatus in the sleep mode.
Fig. 7 is a functional block diagram showing the structure of a mobile terminal according to the first embodiment.
fig. 8 is an explanatory diagram showing a reception state of the reference signals transmitted from the plurality of relay devices at the mobile terminal 20.
fig. 9 is a functional block diagram showing the structure of a base station according to the first embodiment.
Fig. 10 is a sequence diagram showing the operation of the communication system according to the first embodiment.
Fig. 11 is a functional block diagram showing the configuration of a relay apparatus according to the second embodiment.
Fig. 12 is a functional block diagram showing the structure of a mobile terminal according to the second embodiment.
fig. 13 is a functional block diagram showing the structure of a base station according to the second embodiment.
Fig. 14 is a sequence diagram showing the operation of the communication system according to the second embodiment.
Fig. 15 is an explanatory diagram showing a modification 1 of the method for acquiring the location information of the mobile terminal.
Fig. 16 is an explanatory diagram showing a modification 2 of the method for acquiring the location information of the mobile terminal.
fig. 17 is an explanatory diagram showing a modification 3 of the method for acquiring the location information of the mobile terminal.
Detailed Description
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that in the specification and the drawings, elements having substantially the same function and structure are denoted by the same reference numerals, and repeated description is omitted.
in the description and the drawings, a plurality of constituent elements having substantially the same functional configuration are distinguished from each other by having different letters added after the same reference numeral. For example, a plurality of elements having substantially the same functional structure are distinguished from each other as appropriate in the form of the mobile terminals 20A, 20B, and 20C. However, the same reference numerals are assigned only if it is not particularly necessary to distinguish each of a plurality of elements having substantially the same functional structure. For example, if it is not particularly necessary to distinguish between the mobile terminals 20A, 20B and 20C, they are simply referred to as the mobile terminals 20.
Further, the specific embodiments will be described in the following order.
1. overview of a communication System
2. First embodiment
2-1. Structure of relay device
2-2. Structure of mobile terminal
2-3. Structure of base station
2-4. operation of communication System
3. Second embodiment
3-1. Structure of Relay device
3-2. Structure of mobile terminal
3-3. Structure of base station
3-4. operation of communication System
3-5 modification 1
3-6 modification 2
3-7 modification 3
3-8 modification example 4
4. Summary of the invention
<1. overview of communication System >
Referring first to fig. 1-4, a communication system 1 in accordance with an embodiment of the present invention is briefly described.
Fig. 1 is an explanatory diagram showing the configuration of a communication system 1 according to an embodiment of the present invention. As shown in fig. 1, a communication system 1 according to an embodiment of the present invention includes a plurality of base stations 10A, 10B, and 10C, a backbone network (backhaul) 12, a plurality of mobile terminals 20A, 20B, 20C, and a plurality of relay devices 30A, 30B, 30C, and 30D.
The plurality of base stations 10A, 10B, and 10C manage communication with the mobile terminal 20 existing in its radio wave coverage. For example, the base station 10A manages a communication schedule of the mobile terminal 20C existing in the radio wave coverage of the base station 10A, and communicates with the mobile terminal 20C according to the communication schedule.
Further, the plurality of base stations 10A, 10B, and 10C can also communicate with the mobile terminal 20 in its radio wave coverage via the relay apparatus 30. In this case, the plurality of base stations 10A, 10B, and 10C manage the communication schedule of the relay device 30, and the communication schedule between the relay device 30 and the mobile terminal 20. For example, the base station 10A manages the communication schedule of the relay apparatus 30A in the radio wave coverage of the base station 10A, and the communication schedule between the relay apparatus 30A and the mobile terminals 20A and 20B.
in the present description, the management of the communication schedule will be described with emphasis on the centralized control by the base station 10, but the present invention is not limited to such an example. For example, the communication schedule may be managed by the relay device 30 (distributed schedule).
Further, a plurality of base stations 10A, 10B, and 10C are connected via a backbone network 12. The plurality of base stations 10A, 10B, and 10C can exchange various communication information via the backbone network 12.
The relay device 30 relays communication between the base station 10 and the mobile terminal 20. Specifically, in the downlink, the relay apparatus 30 receives a signal transmitted from the base station 10 and then transmits the amplified signal to the mobile terminal 20. By performing such relaying, the relay apparatus 30 can increase the signal-to-noise ratio as compared to when a signal is directly transmitted from the base station 10 to the mobile terminal 20 in the vicinity of the cell edge.
Similarly, also in the uplink, the relay device 30 relays signals transmitted from the mobile terminal 20 to the base station 10, thereby maintaining a high signal-to-noise ratio. In addition, an example in which only the relay apparatus 30A exists in the cell provided by the base station 10A is shown in fig. 1, but a plurality of relay apparatuses 30 may exist in the cell provided by the base station 10A. Referring now to FIG. 2, the link names are organized.
fig. 2 is an explanatory diagram showing respective links in the communication system 1 according to the embodiment of the present invention. As shown in fig. 2, the direct communication path between the base station 10 and the mobile terminal 20 is referred to as a direct link. In addition, a communication path between the base station 10 and the relay device 30 is referred to as a relay link, and a communication link between the relay device 30 and the mobile terminal 20 is referred to as an access link.
As described above, the mobile terminal 20 communicates with the base station 10 directly or via the relay device 30. In addition, as data to be transmitted/received by the mobile terminal 20, audio data, music data such as music, lectures, radio broadcasting programs, still image data such as photographs, files, pictures, charts, video data such as movies, television programs, video programs, game images, and the like can be cited.
Referring now to fig. 3, a structure of a radio frame used in the communication system 1 according to the present embodiment is explained.
Fig. 3 is an explanatory diagram showing an exemplary structure of a radio frame used in the communication system 1 according to the present embodiment. As shown in fig. 3, each radio frame is 10ms in length. In addition, each radio frame is composed of 10 subframes #0 to #9 having a length of 1 ms.
In addition, each subframe is composed of 2 slots of 0.5ms, and each slot of 0.5ms is composed of 7 OFDM (orthogonal frequency division multiplexing) symbols.
In addition, the 5 th and 6 th OFDM symbols of the 1 st 0.5ms slot included in the subframes #0 and #5 are used for transmission of the synchronization reference signal. The mobile terminal 20 performs cell search and synchronization processing based on the reference signal transmitted from the base station 10 or the relay apparatus 30.
In addition, the base station 10 allocates time for communication with the mobile terminal 20 on a per 0.5ms slot basis. In addition, in order to separate the uplink and the downlink, FDD (frequency division duplex) and TDD (time division duplex) are used.
The operation modes of the mobile terminal 20 and the relay device 30 are explained below.
(working mode of Mobile terminal)
Fig. 4 is an explanatory diagram showing an operation mode of the mobile terminal 20 according to LTE. As shown in fig. 4, the operation modes include LTE _ DETACHED, LTE _ ACTIVE, and LTE _ IDLE.
After startup, the mobile terminal 20 enters an operating mode called LTE _ DETACHED. In LTE _ DETACHED mode, the IP address is not assigned and the home cell is unknown.
Subsequently, the mobile terminal 20 becomes LTE _ ACTIVE (ACTIVE mode). In the active mode, cell synchronization and IP address setting of the mobile terminal are performed. In addition, both the state in which cell synchronization is achieved and the state in which cell synchronization is not achieved are included in the active mode. As long as the mobile terminal 20 is in a state where cell synchronization is achieved, the mobile terminal 20 can perform communication regardless of uplink or downlink.
Further, in order to reduce power consumption, the mobile terminal 20 transitions from the active mode to LTE _ IDLE (sleep mode). In the sleep mode, the mobile terminal 20 performs DRX (discontinuous reception). That is, the mobile terminal 20 intermittently receives the signal transmitted from the base station 10 at predetermined periods. Thus, according to the sleep mode, power consumption can be reduced.
When the mobile terminal 20 operates in the sleep mode, although the IP address is set, the network side including the base station 10 is not allowed to sense the cell to which the mobile terminal 20 belongs. The network side senses the location of the mobile terminal 20 at a granularity of a plurality of cells called tracking areas. Thus, the network side transmits L1/L2 signaling in which paging information for paging the mobile terminal 20 is described to the cells in the tracking area in accordance with the DRX cycle.
On the other hand, the mobile terminal 20 receives L1/L2 signaling in which downlink control information such as paging information and scheduling information is described according to the DRX cycle. Subsequently, the mobile terminal 20 determines whether the mobile terminal 20 is paged, i.e., whether there is a communication delivered to the mobile terminal 20, according to the paging information or the scheduling information, and transitions to the active mode as appropriate.
In addition, according to LTE, LTE-enhanced discussed in 3GPP is considered. LTE is a communication scheme based on an OFDM demodulation scheme. Since OFDM uses subcarriers, each mobile terminal 20 is able to communicate while avoiding interference by utilizing different subcarriers or different time slots. More particularly, according to LTE, one resource block is defined by 12 subcarriers and 7 OFDM symbols. Communication resources are allocated to each mobile terminal 20 on a per resource block basis.
(operation mode of Relay device)
According to the present embodiment, since there are a plurality of relay apparatuses 30 existing in the cell provided by the base station 10, the sleep mode is also implemented in the relay apparatuses 30 from the viewpoint of reducing power consumption. In case of operating in the sleep mode, the relay device 30 receives L1/L2 signaling transmitted from the base station 10 in the DRX cycle.
Further, in the case of operating in the active mode, the relay device 30 determines the presence or absence of communication delivered to the relay device 30 by referring to the scheduling information included in the L1/L2 signaling transmitted at intervals of 1 ms. Subsequently, in the absence of communication delivered to the relay apparatus 30, when communication delivered to the relay apparatus 30 is absent for more than a period of time, the relay apparatus 30 may be transitioned to the sleep mode.
In addition, the distributed scheduling is also based on the scheduling of the base station 10. Thus, in the case where neither an uplink nor a downlink is specified for the relay apparatus 30 without scheduling by the base station 10, neither an access link nor a relay link is used. Thus, in the case where neither an uplink nor a downlink is specified for the relay apparatus 30, there may be a direct link, but at least communication via the relay apparatus 30 will not be performed, so that the relay apparatus 30 can shift to the sleep mode.
(background of the embodiment)
the mobile terminal 20 determines its home base station 10 based on cell synchronization or the reception strength of a signal transmitted from the base station 10. Specifically, the mobile terminal 20 performs synchronization processing and measurement of reception intensity by using reference signals transmitted in the 5 th and 6 th OFDM symbols in the 1 st 0.5ms slots included in the subframes #0 and #5 shown in fig. 3.
In the case of operating in the same manner as LTE, a method may be conceived in which the mobile terminal 20 receives the reference signal transmitted from the corresponding relay apparatus 30 and then selects the relay apparatus 30 to be used, based on the reception strength of the reference signal. In addition, the relay device 30 may transmit the reference signal in a slot designated by LTE or in another slot.
However, if the relay apparatus 30 operating in the sleep mode does not transmit the reference signal, the mobile terminal 20 cannot receive the reference signal from the relay apparatus 30 operating in the sleep mode, so that it is difficult to appropriately select the relay apparatus 30.
Further, the basis as to whether the relay device 30 is to be used or not can be as follows.
When comparing the reception strength of the signal transmitted by the mobile terminal 20 at the relay device 30 and at the base station 10, it is of great importance to perform the relay if the reception strength at the relay device 30 is high.
Relaying is less meaningful if the reception strength at the base station 10 is high.
In addition, if the difference between the reception strengths is small, it makes little sense to relay.
Moreover, even if the difference between the two reception strengths is large, the significance of relaying is not great when the reception strength at the base station 10 is sufficiently high. In addition, the case where the reception intensity is sufficiently high is a case where a sufficient SNR can be obtained compared to a required SNR of a demodulation scheme used.
That is, if the relay device 30 is in the active mode, the base station 10 can determine whether the use of the relay device 30 is effective by comparing the reception strength at the relay device 30 with the reception strength at the base station 10.
However, if the relay device 30 is in the sleep mode so that the relay device 30 cannot receive the signal transmitted by the mobile terminal 20, the base station 10 cannot obtain the reception strength at the relay device 30, so that it is difficult to appropriately determine whether the use of the relay device 30 is effective.
Thus, the first and second embodiments of the present invention have been completed in view of the above-described background. According to the first and second embodiments, the relay device 30 to be used for communication between the base station 10 and the mobile terminal 20 can be determined from among one or more relay devices 30 having a sleep mode. Next, details of the first embodiment and the second embodiment are explained with reference to fig. 5 to 17.
<2 > first embodiment
(2-1. Structure of Relay device)
Fig. 5 is a functional block diagram showing the configuration of the relay apparatus 30 according to the first embodiment. As shown in fig. 5, the relay device 30 includes a plurality of antennas 320a to 320n, an analog processing unit 324, an AD/DA converter 328, and a digital processing unit 330, and performs L2 relay.
The plurality of antennas 320a-320n each receive a radio signal from the base station 10 or the mobile terminal 20, obtain a high frequency electric signal, and then supply the high frequency signal to the analog processing unit 324. Each of the antennas 320a to 320n transmits a radio signal to the base station 10 or the mobile terminal 20 based on the high-frequency signal supplied from the analog processing unit 324. Since the relay device 30 is provided with the plurality of antennas 320a to 320n as described above, MIMO (multiple input multiple output) communication or diversity communication is possible.
The analog processing unit 324 converts the high frequency signals supplied from the plurality of antennas 320a to 320n into baseband signals by performing analog processing such as amplification, filtering, down conversion, and the like. In addition, the analog processing unit 324 converts the baseband signal supplied from the AD/DA converter 328 into a high-frequency signal.
The AD/DA converter 328 converts the analog baseband signal supplied from the analog processing unit 324 into a digital format, and then supplies the digital baseband signal to the digital processing unit 330. In addition, the AD/DA converter 328 converts the digital baseband signal supplied from the digital processing unit 330 into an analog format, and then supplies the analog baseband signal to the analog processing unit 324.
the digital processing unit 330 includes a synchronization unit 332, a decoder 334, a buffer 338, an encoder 340, a control unit 342, a DRX cycle holding unit 344, and a DTX cycle holding unit 346. Among them, the synchronization unit 332, the decoder 334, the encoder 340, and the like function as a transmission unit and a reception unit for communicating with the base station 10 and the mobile terminal 20, together with the plurality of antennas 320a to 320n, the analog processing unit 324, and the AD/DA converter 328.
The reference signal transmitted from the base station 10 is supplied from the AD/DA converter 328 to the synchronizing section 332, and the synchronizing section 332 completes the synchronization process of the radio frame based on the reference signal. Specifically, the synchronization unit 332 completes synchronization of the radio frame by calculating correlation between the reference signal and the known sequence pattern and detecting the peak position of the correlation.
The decoder 334 decodes the baseband signal supplied from the AD/DA converter 328, and obtains relay data concerning the base station 10 or the mobile terminal 20. In addition, for example, the decoding may include MIMO reception processing, OFDM demodulation processing, error correction processing, and the like.
The buffer 338 temporarily holds the relay data for the base station 10 or the mobile terminal 20 obtained by the decoder 334. Subsequently, in the transmission time of the access downlink to the mobile terminal 20, the relay data to the mobile terminal 20 is read out from the buffer 338 to the encoder 340 in accordance with the control of the control unit 342. Likewise, in the transmission time of the relay uplink to the base station 10, relay data to the base station 10 is read out from the buffer 338 to the encoder 340 in accordance with the control of the control unit 342.
the encoder 340 encodes the data supplied from the buffer 338 and then supplies the encoded data to the AD/DA converter 328. In addition, for example, the encoding may include a MIMO transmission process and an OFDM demodulation process.
the control unit 342 controls transmission processing, reception processing, transition of the operation mode, and the like of the relay apparatus 30. Specifically, in the case where the relay device 30 operates in the sleep mode, the control unit 342 controls the relay device 30 so as to receive the L1/L2 signaling in accordance with the DRX cycle held in the DRX cycle holding unit 344. Subsequently, the control unit 342 refers to the L1/L2 signaling decoded with the decoder 334 and shifts the operation mode to the active mode in the presence of communication delivered to the relay apparatus 30. In the case where an instruction to shift to the active mode is received from the base station 10, the control unit 342 also shifts the operation mode to the active mode.
In addition, in the case where the relay device 30 operates in the sleep mode, the control unit 342 controls the relay device 30 so that the reference signal is transmitted in accordance with the DTX (discontinuous transmission) period held in the DTX period holding unit 346.
fig. 6 is an explanatory diagram showing an operation of the relay apparatus 30 in the sleep mode. As shown in fig. 6, in the sleep mode, the relay device 30 receives L1/L2 signaling according to a DRX cycle (L1/L2Rx), and transmits a reference signal (RefTx) according to a DTX cycle.
More specifically, the relay device 30 may perform transmission of the reference signal in the 5 th and 6 th OFDM symbols included in the 1 st 0.5ms slot in the subframes #0 and # 5. In addition, the relay device 30 may transmit the reference signal only in one radio frame among the 10 radio frames, instead of transmitting the reference signal in all the radio frames.
In addition, each relay device 30 transmits the reference signal with a different spreading code. Thus, the mobile terminal 20 is allowed to receive the reference signal from each relay device 30 by code division, and identify the relay device 30 as the transmission source based on the spreading code used.
(2-2. Structure of Mobile terminal)
The structure of the mobile terminal 20 is explained below with reference to fig. 7 and 8.
Fig. 7 is a functional block diagram showing the structure of the mobile terminal 20 according to the first embodiment. As shown in fig. 7, the mobile terminal 20 includes a plurality of antennas 220a to 220n, an analog processing unit 224, an AD/DA converter 228, and a digital processing unit 230.
The plurality of antennas 220a to 220n each receive a radio signal from the base station 10 or the relay apparatus 30, obtain a high-frequency electric signal, and then supply the high-frequency signal to the analog processing unit 224. In addition, the plurality of antennas 220a to 220n each transmit a radio signal to the base station 10 or the relay apparatus 30 in accordance with the high-frequency signal supplied from the analog processing unit 224. As described above, since the mobile terminal 20 includes the plurality of antennas 220a to 220n, MIMO communication or diversity communication can be performed.
The analog processing unit 224 converts the high-frequency signals supplied from the plurality of antennas 220a to 220n into baseband signals by performing analog processing such as amplification, filtering, down-conversion, and the like. Further, the analog processing unit 224 converts the baseband signal supplied from the AD/DA converter 228 into a high frequency signal.
The AD/DA converter 228 converts the analog baseband signal supplied from the analog processing unit 224 into a digital format, and then supplies the digital baseband signal to the digital processing unit 230. In addition, the AD/DA converter 228 converts the digital baseband signal supplied from the digital processing unit 230 into an analog format, and then supplies the analog baseband signal to the analog processing unit 224.
The digital processing unit 230 includes a synchronization unit 232, a decoder 234, a relay device determination unit 236, a transmission data generation unit 238, an encoder 240, a control unit 242, a DRX cycle holding unit 244, and a DTX cycle holding unit 246. Among them, the synchronization unit 232, the decoder 234, the encoder 240, and the like function as a transmission unit and a reception unit for communicating with the base station 10 and the relay device 30, together with the plurality of antennas 220a to 220n, the analog processing unit 224, and the AD/DA converter 228.
The reference signal transmitted from the base station 10 or the relay device 30 is supplied from the AD/DA converter 228 to the synchronization unit 232, and the synchronization unit 232 completes the synchronization process of the wireless frame in accordance with the reference signal. Specifically, the synchronization unit 232 performs synchronization of the radio frames by calculating correlation between the reference signal and the known sequence pattern and detecting the peak position of the correlation.
The decoder 234 decodes the baseband signal supplied from the AD/DA converter 228, thereby obtaining received data. In addition, for example, the decoding may include MIMO reception processing and OFDM demodulation processing.
The relay device determining unit 236 determines the relay device 30 to be used for communication with the base station 10 from among the plurality of relay devices 30, according to the magnitude of correlation of the reference signal obtained by the synchronization unit 232. Specifically, the relay device determining unit 236 may determine the relay device 30 that is the transmission source of the reference signal having the highest correlation as the relay device 30 to be used for communication with the base station 10.
The transmission data generation unit 238 is supplied with information indicating the relay device 30 determined by the relay device determination unit 236, generates transmission data including the information, and supplies the transmission data to the encoder 240.
The encoder 240 encodes the transmission data supplied from the transmission data generation unit 238 and then supplies the encoded transmission data to the AD/DA converter 228. In addition, for example, the encoding may include a MIMO transmission process and an OFDM demodulation process.
The control unit 242 controls the transmission process, the reception process, and the transition of the operation mode of the mobile terminal 20. For example, in the case where the mobile terminal 20 operates in the sleep mode, the control unit 242 controls the mobile terminal 20 so as to receive the L1/L2 signaling in the DRX cycle maintained in the DRX cycle maintaining unit 244. Subsequently, the control unit 242 transitions the operating mode to the active mode in the presence of communications delivered to the mobile terminal 20 with reference to the L1/L2 signaling decoded by the decoder 234.
Further, in the case of operating in the sleep mode, the control unit 242 controls such that the mobile terminal 20 performs reception processing in accordance with the DTX cycle held in the DTX cycle holding unit 246, thereby receiving the reference signal transmitted from the relay apparatus 30 (including the relay apparatus 30 operating in the sleep mode).
Fig. 8 is an explanatory diagram showing a reception state of the reference signals transmitted from the plurality of relay devices 30 at the mobile terminal 20. As shown in fig. 8, the mobile terminal 20 receives reference signals from the relay devices 30A and 30B operating in the active mode every 5 subframes (5 ms). On the other hand, the mobile terminal 20 receives the reference signal from the relay device 30C operating in the sleep mode at every 15 subframes (15ms) in accordance with the DTX cycle held in the DTX cycle holding section 246.
(2-3. Structure of base station)
Next, with reference to fig. 9, the structure of the base station 10 according to the first embodiment is explained.
Fig. 9 is a functional block diagram showing the structure of the base station 10 according to the first embodiment. As shown in fig. 9, the base station 10 includes a plurality of antennas 120a to 120n, an analog processing unit 124, an AD/DA converter 128, and a digital processing unit 130.
the plurality of antennas 120a to 120n each receive a radio signal from the relay device 30 or the mobile terminal 20, thereby obtaining a high-frequency electric signal, and supply the high-frequency signal to the analog processing unit 124. In addition, the plurality of antennas 120a to 120n each transmit a radio signal to the relay device 30 or the mobile terminal 20 according to the high-frequency signal supplied from the analog processing unit 124. Since the base station 10 is provided with the plurality of antennas 120a to 120n as described above, it can perform MIMO communication or diversity communication.
The analog processing unit 124 converts the high-frequency signals supplied from the plurality of antennas 120a to 120n into baseband signals by performing analog processing such as amplification, filtering, down-conversion, and the like. In addition, the analog processing unit 124 converts the baseband signal supplied from the AD/DA converter 128 into a high-frequency signal.
The AD/DA converter 128 converts the analog baseband signal supplied from the analog processing unit 124 into a digital format, and supplies the digital baseband signal to the digital processing unit 130. In addition, the AD/DA converter 128 converts the digital baseband signal supplied from the digital processing unit 130 into an analog format, and then supplies the analog baseband signal to the analog processing unit 124.
Digital processing unit 130 includes decoder 134, encoder 140, and control unit 142. Among them, the decoder 134, the encoder 140, and the like function as a transmitting unit and a receiving unit for communicating with the relay device 30 and the mobile terminal 20, together with the plurality of antennas 120a to 120n, the analog processing unit 124, and the AD/DA converter 128.
The decoder 134 decodes the baseband signal supplied from the AD/DA converter 128, thereby obtaining received data. In addition, for example, the decoding may include MIMO reception processing, OFDM demodulation processing, error correction processing, and the like.
The encoder 140 encodes the transmission data and then supplies the encoded transmission data to the AD/DA converter 128. In addition, for example, the encoding may include a MIMO transmission process and an OFDM demodulation process.
The control unit 142 (mode control unit) controls transmission processing and reception processing of the base station 10, transition of the operation mode of the relay device 30, and the like. For example, when receiving information indicating a relay device 30 to be used for communication with the base station 10 from the mobile terminal 20, if the relay device 30 is operating in the sleep mode, the control unit 142 issues an instruction to transition to the active mode with L1/L2 signaling.
Here, since the relay device 30 receives the L1/L2 signaling in the DRX cycle even when operating in the sleep mode, the relay device 30 transitions to the active mode in accordance with an instruction from the base station 10 included in the L1/L2 signaling. As a result, the base station 10 and the mobile terminal 20 can communicate via the relay device 30 that has transitioned to the active mode.
(2-4. operation of communication System)
The structures of the relay device 30, the mobile terminal 20, and the base station 10 are explained above. Next, with reference to fig. 10, the operation of the communication system 1 according to the first embodiment is explained.
Fig. 10 is a sequence diagram showing the operation of the communication system 1 according to the first embodiment. As shown in fig. 10, each relay device 30 transmits a reference signal (S404). Here, the relay apparatus 30C operating in the sleep mode transmits the reference signal in the DTX cycle, so that the frequency of transmitting the reference signal is low compared to the relay apparatus 30A operating in the active mode.
Subsequently, the relay device determining unit 236 of the mobile terminal 20 obtains the reception strength (the magnitude of correlation) of the reference signal transmitted from each relay device 30, and determines the relay device 30 to be used for communication with the base station 10 (S408). In addition, the present sequence diagram shows an example in which the relay device 30C is determined as the relay device 30 to be used for communication with the base station 10.
Subsequently, the mobile terminal 20 notifies the base station 10 of information indicating the determined relay device 30C using the control channel of the uplink of the direct link (S412). Since the relay device 30C notified by the mobile terminal 20 is in the sleep mode, the control unit 142 of the base station 10 transmits a control signal indicating a transition from the sleep mode to the active mode using L1/L2 signaling (S416).
The relay device 30C operating in the sleep mode monitors the L1/L2 signaling according to the DRX cycle, and transitions to the active mode when an instruction to transition from the sleep mode to the active mode is issued in the L1/L2 signaling (S420). Subsequently, the relay device 30C starts transmitting the reference signal at a normal time interval (S424).
Subsequently, when receiving the reference signal from the relay device 30C that has transitioned to the active mode, the synchronization unit 232 of the mobile terminal 20 establishes synchronization of the radio frame (S428). Thereby, the mobile terminal 20 and the base station 10 are enabled to perform uplink communication and downlink communication by the relay device 30C (S432). In addition, when there is no more mobile terminal 20 synchronized with the relay device 30C, the relay device 30C may transition from the active mode to the sleep mode according to an instruction from the base station 10.
<3. second embodiment >
the first embodiment of the present invention has been explained above. The second embodiment of the present invention is explained below. Unlike the relay apparatus 30 of the first embodiment, the relay apparatus 30' of the second embodiment does not transmit the reference signal in the sleep mode. Thus, the second embodiment is also different from the first embodiment in other structural aspects, as described below.
(3-1. Structure of Relay device)
First, referring to fig. 11, a configuration of a relay apparatus 30' according to the second embodiment is explained.
Fig. 11 is a functional block diagram showing the configuration of a relay apparatus 30' according to the second embodiment. As shown in fig. 11, the relay device 30' includes a plurality of antennas 320a to 320n, an analog processing unit 324, an AD/DA converter 328, and a digital processing unit 330, and performs L2 relay. In addition, the digital processing unit 330 includes a synchronization unit 332, a decoder 334, a buffer 338, an encoder 340, a control unit 342, and a DRX cycle holding unit 344.
Unlike the relay device 30 according to the first embodiment, the relay device 30' according to the second embodiment does not have the DTX period holding unit 346. That is, in the sleep mode, the relay device 30' performs intermittent reception according to the DRX cycle, but does not transmit the reference signal.
In addition, the plurality of antennas 320a to 320n, the analog processing unit 324, the AD/DA converter 328, and the like may be configured to be substantially the same as the relay apparatus 30 according to the first embodiment, so that detailed description thereof is omitted.
(3-2. Structure of Mobile terminal)
next, referring to fig. 12, the structure of a mobile terminal 20' according to the second embodiment is explained.
Fig. 12 is a functional block diagram showing the structure of a mobile terminal 20' according to the second embodiment. As shown in fig. 12, the mobile terminal 20' includes a plurality of antennas 220a to 220n, an analog processing unit 224, an AD/DA converter 228, and a digital processing unit 230. In addition, the digital processing unit 230 includes a synchronization unit 232, a decoder 234, a relay device determination unit 236, a transmission data generation unit 238, an encoder 240, a control unit 242, and a DRX cycle holding unit 244.
As described above, the relay device 30' according to the second embodiment does not transmit the reference signal in the sleep mode. Thus, the mobile terminal 20' according to the second embodiment does not possess the DTX period maintaining unit 346. That is, in the sleep mode, the mobile terminal 20' according to the second embodiment performs intermittent reception according to the DRX cycle, but does not perform intermittent reception according to the DTX cycle.
In addition, the plurality of antennas 220a to 220n, the analog processing unit 224, the AD/DA converter 228, and the like may be configured to be substantially the same as the mobile terminal 20 according to the first embodiment, so that detailed descriptions thereof are omitted.
(3-3. Structure of base station)
Next, referring to fig. 13, the structure of a base station 10' according to the second embodiment is explained.
Fig. 13 is a functional block diagram showing the structure of a base station 10' according to the second embodiment. As shown in fig. 13, the base station 10' includes a plurality of sets of antennas 122a to 122n for respective sectors, an analog processing unit 124, an AD/DA converter 128, and a digital processing unit 130.
The cell formed by base station 10' is made up of a number of sectors, each set of antennas 122a-122n transmitting and receiving with respect to a corresponding sector. In addition, the analog processing unit 124, the AD/DA converter 128, and the like must be compatible with sector communication, but essentially they may be configured to be substantially the same as the base station 10 according to the first embodiment, and thus detailed description thereof is omitted.
The digital processing unit 130 includes a decoder 134, an encoder 140, a control unit 142, a terminal position acquisition unit 152, a relay device position holding unit 154, and a selection unit 156.
The terminal position acquisition unit 152 acquires information indicating the presence position of the mobile terminal 20'. Specifically, the terminal position acquisition unit 152 detects the arrival direction of the radio signal, i.e., the direction in which the mobile terminal 20 'exists, according to which of the plurality of sets of antennas 122a to 122n receives the radio signal transmitted from the mobile terminal 20'. In addition, the method of detecting the presence direction is not limited to the above, and an arrival direction estimation algorithm capable of electronically obtaining the directivity may be used.
In addition, the terminal position acquisition unit 152 detects the distance between the mobile terminal 20' and the base station 10' based on the reception intensity of the radio signal transmitted from the mobile terminal 20 '. For example, the terminal position acquisition unit 152 may compare the transmission power of the radio signal of the mobile terminal 20 'and the reception strength of the radio signal at the base station 10', and detect the distance between the mobile terminal 20 'and the base station 10' from the propagation loss. In addition, a case where the mobile terminal 20 'sets the transmission power individually is also conceivable, so that the mobile terminal 20' can transmit information indicating the transmission power, from which the terminal position acquisition unit 152 can obtain the transmission power of the radio signal. In addition, for example, the relationship between the propagation loss in free space and the distance is expressed as the following formula 1.
L20 log10(4 pi d/lambda) [ dB ] (formula 1)
d is distance
λ wavelength
By detecting the presence direction of the mobile terminal 20' and the distance to the base station 10' in the above manner, the terminal position acquisition unit 152 can perceive the presence position of the mobile terminal 20 '. In addition, since the timing at which the base station 10' receives the signal transmitted by the mobile terminal 20' differs depending on the distance between the base station 10' and the mobile terminal 20', the terminal position acquisition unit 152 can estimate the distance to the mobile terminal 20' from the reception timing.
Further, the relay device position holding unit 154 holds the position information of each relay device 30'. By detecting the existence direction of the relay device 30' and the distance to the base station 10' in the above-described manner based on the signal transmitted from the relay device 30' in the active mode, the base station 10' can obtain the position information of each relay device 30 '.
The selection unit 156 selects the relay apparatus 30 'suitable for the communication with the mobile terminal 20' with reference to the position information of the mobile terminal 20 'obtained by the terminal position acquisition unit 152 and the position information of the respective relay apparatuses 30' held by the relay apparatus position holding unit 154. For example, the selection unit 156 selects the relay device 30 'closest to the mobile terminal 20'.
In the case where the relay device 30' selected by the selection unit 156 is operating in the sleep mode, the control unit 142 issues an instruction to transition to the active mode using L1/L2 signaling. Even when operating in the sleep mode, the relay device 30 'receives the L1/L2 signaling in accordance with the DRX cycle, thereby transitioning to the active mode in accordance with an instruction from the base station 10' included in the L1/L2 signaling. As a result, the relay device 30' starts the transmission of the reference signal, so that the mobile terminal 20' can determine the relay device 30' to be used for communication with the base station 10' from the reference signal transmitted by the relay device 30 '.
(3-4. operation of communication System)
The structures of the relay device 30', the mobile terminal 20' and the base station 10' are explained above. Next, with reference to fig. 14, the operation of the communication system according to the second embodiment is explained.
Fig. 14 is a sequence diagram showing the operation of the communication system according to the second embodiment. As shown in fig. 14, the relay device 30'a operating in the active mode transmits the reference signal, and the relay device 30' C operating in the sleep mode does not transmit the reference signal (S504). When the mobile terminal 20 'transmits a radio signal (S508), the terminal position acquisition unit 152 of the base station 10' estimates the position of the mobile terminal 20 'by detecting the arrival direction of the radio signal and the distance to the mobile terminal 20' (S512).
Further, the selection unit 156 of the base station 10' selects the relay device 30' in the vicinity of the mobile terminal 20' (S516). Here, it is assumed that the selection unit 156 of the base station 10 'selects the relay device 30' C. In this case, since the relay device 30'C is in the sleep mode, the control unit 142 of the base station 10' transmits a control signal indicating a transition from the sleep mode to the active mode using L1/L2 signaling (S520).
The relay device 30' C operating in the sleep mode monitors the L1/L2 signaling according to the DRX cycle, and transitions to the active mode when an instruction to transition from the sleep mode to the active mode is issued in the L1/L2 signaling (S524). Subsequently, the relay device 30' C starts transmission of the reference signal (S528).
Subsequently, the relay device determining unit 236 of the mobile terminal 20 'obtains the reception strength (the magnitude of correlation) of the reference signal transmitted from each relay device 30', and determines the relay device 30 'to be used for communication with the base station 10' (S532). Here, it is assumed that the relay device selection unit 236 of the mobile terminal 20' determines to communicate with the base station 10' using the relay device 30' C. In this case, the mobile terminal 20' notifies the base station 10' of information indicating the determined relay device 30' C using the control channel of the direct uplink (S536).
As a result, the mobile terminal 20 'and the base station 10' are enabled to perform uplink communication and downlink communication with the relay apparatus 30'C according to the scheduling of the base station 10' (S540). In addition, when there is no more mobile terminal 20 'synchronized with the relay device 30' C, the relay device 30'C may transition from the active mode to the sleep mode according to an instruction from the base station 10'.
(3-5. modified example 1)
the second embodiment is explained above. However, the method of the terminal position acquisition unit 152 of the base station 10 'acquiring the position information of the mobile terminal 20' is not limited to the above example. Next, modifications 1 to 4 of the method of acquiring the position information of the mobile terminal 20' by the terminal position acquiring unit 152 will be described.
Fig. 15 is an explanatory diagram showing a modification 1 of the method for acquiring the positional information of the mobile terminal 20'. As shown in fig. 15, according to modification 1, although the mobile terminal 20 'belongs to the base station 10' a, it also receives the reference signals transmitted by the base stations 10'B and 10' C. Thus, the mobile terminal 20' measures the reception strength of the reference signal transmitted by each base station 10' and transmits the reception strength information obtained by the measurement to the base station 10' a.
The terminal position acquisition unit 152 of the base station 10' a estimates the position of the mobile terminal 20' from the reception intensity information received from the mobile terminal 20 '. For example, the terminal position acquisition unit 152 may estimate the distance from each base station 10' to the mobile terminal 20' based on the reception strength of the reference signal transmitted from each base station 10' at the mobile terminal 20', and estimate the position satisfying the respective estimated distances as the position of the mobile terminal 20 '.
(3-6. modification 2)
Fig. 16 is an explanatory diagram showing a modification 2 of the method for acquiring the positional information of the mobile terminal 20'. As shown in fig. 16, according to modification 2, not only the base station 10' a but also the base stations 10' B and 10' C receive radio signals transmitted by the mobile terminal 20' belonging to the base station 10' a. Each base station 10' then estimates the direction and distance of the mobile terminal 20' from the radio signals received from the mobile terminal 20 '. In addition, the base stations 10'B and 10' C transmit information related to the estimated position of the mobile terminal 20 'to the base station 10' a via the backbone network 12.
Thus, by combining various pieces of information relating to the position of the mobile terminal 20 'estimated by the base station 10', the terminal position acquisition unit 152 of the base station 10'a can obtain the position information of the mobile terminal 20'. In addition, the base stations 10'B and 10' C may transmit only the reception strength of the radio signal received from the mobile terminal 20 'to the base station 10' a, and the base station 10'a may estimate the position of the mobile terminal 20' based on the reception strength information.
(3-7. modification 3)
Fig. 17 is an explanatory diagram showing a modification 3 of the method for acquiring the positional information of the mobile terminal 20'. As shown in fig. 17, according to modification 3, the mobile terminal 20' receives the reference signal transmitted from the base station 10' a and each relay apparatus 30' operating in the active mode. Subsequently, the mobile terminal 20 'measures the reception strength of the reference signal transmitted by the base station 10' a and each relay device 30 'and transmits the reception strength information obtained by the measurement to the base station 10' a.
The terminal position acquisition unit 152 of the base station 10' a estimates the position of the mobile terminal 20' from the reception intensity information received from the mobile terminal 20 '. For example, the terminal position acquisition unit 152 may estimate the distances from the base station 10' and each relay device 30' to the mobile terminal 20' based on the reception strength at the mobile terminal 20' of the reference signals transmitted from the base station 10' a and each relay device 30', and then estimate the position satisfying each estimated distance as the position of the mobile terminal 20 '.
(3-8. modification 4)
Further, according to modification 4, the mobile terminal 20' has a GPS (global positioning system) reception function. The mobile terminal 20' obtains the location information of the mobile terminal 20' using the GPS receiving function and transmits the obtained location information to the base station 10 '. As a result, the terminal position acquisition unit 152 of the base station 10 'is enabled to acquire the position information of the mobile terminal 20'.
<4. summary >
As described above, according to the first embodiment of the present invention, the relay device 30 operating in the sleep mode also transmits the reference signal according to the DRX cycle. Accordingly, the mobile terminal 20 can receive not only the reference signal from the relay apparatus 30 operating in the active mode but also the reference signal from the relay apparatus 30 operating in the sleep mode. Thus, the mobile terminal 20 is enabled to determine the relay apparatus 30 to be used for communication with the base station 10 from among the plurality of relay apparatuses 30 including the relay apparatus 30 operating in the sleep mode, and to perform communication via the determined relay apparatus 30.
In addition, according to the second embodiment of the present invention, the base station 10' makes the relay device 30' operating in the sleep mode in the vicinity of the mobile terminal 20' transition to the active mode. Thus, the mobile terminal 20 'becomes able to receive the reference signal from the relay device 30' that previously operated in the sleep mode as well, thereby more appropriately determining the relay device 30 'to be used for communication with the base station 10'.
although the present invention is naturally not limited to the above examples, preferred embodiments of the present invention are described above with reference to the accompanying drawings. Various changes and modifications may be made by those skilled in the art within the scope of the appended claims, and it is to be understood that such changes and modifications naturally fall within the technical scope of the present invention.
For example, the processing steps of the communication system 1 of the present specification do not necessarily have to be executed in chronological order corresponding to the order described as a sequence diagram. For example, the processing steps of the communication system 1 may be performed in a different order from the order shown in the sequence diagram, or may be performed in parallel.
Further, a computer program may also be produced which causes hardware such as a CPU, ROM, RAM, or the like installed in the base station 10, the mobile terminal 20, or the relay apparatus 30 to realize the same functions as the respective components of the base station 10, the mobile terminal 20, or the relay apparatus 30 described above. Further, a storage medium storing the computer program is also provided.

Claims (26)

1. A communication system, comprising:
A mobile terminal;
One or more communication devices for relaying; and
A base station communicating with a mobile terminal via any of the one or more communication devices for relaying,
Wherein the mobile terminal comprises
A receiving unit configured to receive the first reference signal and/or the second reference signal transmitted from the one or more communication devices for relaying, and
A determination unit configured to determine the communication device for relaying based on the first reference signal and/or the second reference signal received by the reception unit from the one or more communication devices for relaying,
Wherein each of the one or more communication devices for relaying transmits a first reference signal according to a first cycle when operating in a power saving mode and transmits a second reference signal according to a second cycle when operating in an active mode,
Wherein the base station comprises:
A mode control unit configured to issue an instruction to transition to an active mode if the selected communication device for relaying operates in a power saving mode, and the communication device for relaying receives the instruction from the base station according to a third cycle,
Wherein the first period is longer than the second period and the third period is shorter than the first period.
2. A communication system according to claim 1, wherein the first period is a discontinuous transmission, DTX, period.
3. The communication system according to claim 1, wherein the first period is longer than a length of a subframe.
4. The communication system according to claim 1, wherein the first period is longer than a length of 10 subframes.
5. The communication system of claim 1, wherein the first reference signal is used for synchronization.
6. a communication control method comprising the steps of:
Receiving, by a mobile terminal, a first reference signal and/or a second reference signal transmitted from one or more communication devices for relaying; and
Determining a communication device for relaying based on a first reference signal and/or a second reference signal received from the one or more communication devices for relaying, wherein each of the one or more communication devices for relaying transmits the first reference signal according to a first cycle when operating in a power saving mode and transmits the second reference signal according to a second cycle when operating in an active mode;
Wherein the communication control method further comprises the steps of:
Issuing an instruction to transition the determined communication apparatus for relaying to an active mode in a case where the determined communication apparatus for relaying operates in a power saving mode, and the communication apparatus for relaying receives the instruction according to a third cycle;
Wherein the first period is longer than the second period and the third period is shorter than the first period.
7. The communication control method according to claim 6, wherein the first period is a Discontinuous Transmission (DTX) period.
8. The communication control method according to claim 6, wherein the first period is longer than a length of a subframe.
9. The communication control method according to claim 6, wherein the first period is longer than a length of 10 subframes.
10. The communication control method according to claim 6, wherein the first reference signal is used for synchronization.
11. A mobile terminal, comprising:
A receiving unit for receiving a first reference signal and/or a second reference signal transmitted from one or more communication apparatuses for relaying;
A determination unit configured to determine a communication apparatus for relaying used for communication with a base station, based on the first reference signal and/or the second reference signal received by the reception unit from the one or more communication apparatuses for relaying; and
A transmitting unit for transmitting information indicating the communication device for relaying determined by the determining unit to the base station,
Wherein each of the one or more communication devices for relaying transmits a first reference signal according to a first cycle when operating in a power saving mode and transmits a second reference signal according to a second cycle when operating in an active mode, the base station issues an instruction to transition the determined communication device for relaying to the active mode if the determined communication device for relaying operates in the power saving mode, and the communication device for relaying receives the instruction according to a third cycle,
And the first period is longer than the second period, and the third period is shorter than the first period.
12. The mobile terminal of claim 11, wherein the first period is a Discontinuous Transmission (DTX) period.
13. The mobile terminal of claim 11, wherein the first periodicity is longer than a length of a subframe.
14. The mobile terminal of claim 11, wherein the first period is longer than a length of 10 subframes.
15. The mobile terminal of claim 11, wherein the first reference signal is used for synchronization.
16. a communication device for relaying, for relaying communication between a mobile terminal and a base station, the mobile terminal comprising a receiving unit configured to receive a first reference signal and/or a second reference signal transmitted from the one or more communication devices for relaying, and a determining unit configured to determine the communication device for relaying based on the first reference signal and/or the second reference signal received by the receiving unit from the one or more communication devices for relaying,
Wherein the communication device for relaying includes:
A transmission unit configured to transmit a first reference signal according to a first period when the communication apparatus for relaying operates in a power saving mode and transmit a second reference signal according to a second period when the communication apparatus for relaying operates in an active mode, wherein the first period is longer than the second period,
A receiving unit configured to receive an instruction to transition to an active mode in a case where the communication apparatus for relaying operates in a power saving mode, wherein the receiving unit receives the instruction from the base station according to a third cycle, the third cycle being shorter than the first cycle, and
a mode control unit configured to transition from a power saving mode to an active mode upon receiving the instruction.
17. The communications device for relaying according to claim 16, wherein the first period is a Discontinuous Transmission (DTX) period.
18. The communication device for relay of claim 16, wherein the first periodicity is longer than a length of a subframe.
19. The communication device for relay of claim 16, wherein the first period is longer than a length of 10 subframes.
20. The communication device for relaying according to claim 16, wherein the first reference signal is used for synchronization.
21. The communication device for relaying according to claim 16, wherein the communication device for relaying
In the case where the communication apparatus for relaying operates in a power saving mode, discontinuous reception is performed, and
The instructions are received from a base station while performing discontinuous reception.
22. A base station configured to communicate with a mobile terminal through one or more communication devices for relaying, wherein the mobile terminal comprises a receiving unit configured to receive a first reference signal and/or a second reference signal transmitted from the one or more communication devices for relaying, and a determining unit configured to determine the communication device for relaying based on the first reference signal and/or the second reference signal received by the receiving unit from the one or more communication devices for relaying,
The base station is configured to communicate with the mobile terminal via the determined communication device for relaying,
Wherein the communication apparatus for relaying operates in a power saving mode in which the communication apparatus for relaying transmits a first reference signal according to a first cycle or an active mode in which the communication apparatus for relaying transmits a second reference signal according to a second cycle and the first cycle is longer than the second cycle,
The base station includes:
A mode control unit configured to issue an instruction to transition the selected communication apparatus for relaying to an active mode if the selected communication apparatus for relaying operates in a power saving mode, wherein the communication apparatus for relaying receives the instruction from the base station according to a third period, and the third period is shorter than the first period.
23. The base station of claim 22, wherein the first period is a Discontinuous Transmission (DTX) period.
24. The base station of claim 22, wherein the first periodicity is longer than a length of a subframe.
25. The base station of claim 22, wherein the first period is longer than a length of 10 subframes.
26. The base station of claim 22, wherein the first reference signal is used for synchronization.
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Families Citing this family (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5540592B2 (en) 2009-07-23 2014-07-02 ソニー株式会社 COMMUNICATION SYSTEM, COMMUNICATION CONTROL METHOD, MOBILE TERMINAL, AND RELAY DEVICE
JP2011066874A (en) 2009-08-17 2011-03-31 Sony Corp Communication system, communication apparatus, communication method, and computer program
JP2011071963A (en) 2009-08-26 2011-04-07 Sony Corp Communication system, apparatus and method and computer program
JP5515558B2 (en) * 2009-09-25 2014-06-11 ソニー株式会社 COMMUNICATION SYSTEM, RELAY DEVICE, AND COMMUNICATION DEVICE
WO2011111214A1 (en) * 2010-03-11 2011-09-15 富士通株式会社 Relay station, base station, mobile station, communication system, and communication method
US8331995B2 (en) 2010-07-07 2012-12-11 Telefonaktiebolaget L M Ericsson (Publ) Secondary radio-nodes for mobile communications networks and related methods
JP5606368B2 (en) * 2011-03-16 2014-10-15 三菱電機株式会社 Wireless communication network system
CN103503330B (en) 2011-05-02 2017-06-06 黑莓有限公司 Use the method and system of the radio communication of remote radio-frequency heads
US20120281555A1 (en) * 2011-05-02 2012-11-08 Research In Motion Limited Systems and Methods of Wireless Communication with Remote Radio Heads
US9014020B2 (en) 2011-05-02 2015-04-21 Blackberry Limited Methods and systems of wireless communication with remote radio heads
US9363753B2 (en) 2011-07-19 2016-06-07 Qualcomm Incorporated Sleep mode for user equipment relays
US9113412B2 (en) * 2011-12-12 2015-08-18 Qualcomm Incorporated Low power node dormant state
JP2013207476A (en) * 2012-03-28 2013-10-07 Fujitsu Ltd Control method of radio communication system, radio base station, radio terminal, and radio communication system
US9560592B2 (en) 2012-04-27 2017-01-31 Qualcomm Incorporated Method and apparatus for signaling in dense network operations
CN104380811B (en) * 2012-06-15 2018-09-14 Lg电子株式会社 Enhance the device and method thereof of multiple-input and multiple-output MIMO signal in a wireless communication system
JP5759428B2 (en) * 2012-07-31 2015-08-05 日本電信電話株式会社 Wireless communication apparatus and wireless communication method
EP2706815A1 (en) * 2012-09-07 2014-03-12 NEC Corporation, Incorporated in Japan Method and system for relaying in a telecommunication network
GB2505900B (en) * 2012-09-13 2015-03-04 Broadcom Corp Methods, apparatus and computer programs for operating a wireless communications device
JP6264752B2 (en) * 2013-06-06 2018-01-24 富士通株式会社 Control method, control device, and communication system
KR102094718B1 (en) * 2013-09-26 2020-05-27 삼성전자주식회사 Relay device and method to select relay node based on learning wireless network
JP6006251B2 (en) * 2014-03-27 2016-10-12 Ｎｅｃプラットフォームズ株式会社 Wireless communication apparatus and power supply control method
WO2016076107A1 (en) * 2014-11-14 2016-05-19 株式会社Ｎｔｔドコモ User device and d2d communications method
WO2016155018A1 (en) * 2015-04-03 2016-10-06 华为技术有限公司 Data transmission method, user equipment and base station
EP3389327B1 (en) * 2015-12-29 2020-03-18 Huawei Technologies Co., Ltd. Terminal device, network device, data transmission method, and wireless communication system
DE102016212002B4 (en) 2016-03-16 2018-05-09 Volkswagen Aktiengesellschaft A method for operating a mobile station, and relay radio station and mobile station for use in the method
US9948368B2 (en) * 2016-04-29 2018-04-17 Sony Corporation Proactive MIMO relaying in wireless communications
CN106341877A (en) * 2016-09-29 2017-01-18 青岛海信移动通信技术股份有限公司 Relay device state control method, relay device and communication system
CN107959972B (en) * 2016-10-18 2020-03-13 宏达国际电子股份有限公司 Environment control system, control device and control method
WO2018142773A1 (en) 2017-02-03 2018-08-09 日本電気株式会社 Communication processing system, communication processing method, communication processing device, and control method and control program for said device
JP6855417B2 (en) * 2018-07-23 2021-04-07 ソフトバンク株式会社 Communication terminal device, and its control method and program
CN109041072A (en) * 2018-08-09 2018-12-18 苏州健雄职业技术学院 A kind of NB-IoT uplink coverage reinforcing system and its working method based on relaying
CN112584389B (en) * 2019-09-29 2022-08-30 成都鼎桥通信技术有限公司 Networking method and communication device
CN113891364A (en) * 2021-10-15 2022-01-04 中国联合网络通信集团有限公司 Control method, communication method and equipment of relay equipment
CN113891366B (en) * 2021-10-15 2024-02-06 中国联合网络通信集团有限公司 Relay device control method, device, system and storage medium
WO2023139846A1 (en) * 2022-01-18 2023-07-27 コニカミノルタ株式会社 Wireless communication system, and management device, relay device, communication control method, and communication control program for same
WO2023175987A1 (en) * 2022-03-18 2023-09-21 日本電気株式会社 Management device, management method, and program

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1263396A (en) * 1999-02-03 2000-08-16 松下电器产业株式会社 Radio communication system
JP2006254155A (en) * 2005-03-11 2006-09-21 Kddi Corp Communications apparatus and connection method to base station by multi-hopping
CN1902868A (en) * 2003-12-30 2007-01-24 艾利森电话股份有限公司 Method and system for wireless communication networks using cooperative relaying
CN1918860A (en) * 2004-02-06 2007-02-21 皇家飞利浦电子股份有限公司 A system and method for hibernation mode for beaconing devices
JP2008235962A (en) * 2007-03-16 2008-10-02 Fujitsu General Ltd Radio communication system
WO2008149598A1 (en) * 2007-06-04 2008-12-11 Sony Corporation Communication system, communication device, communication method, and computer program
JP2009159409A (en) * 2007-12-27 2009-07-16 Kyocera Corp Radio communication system, mobile station, and radio communication method

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6665541B1 (en) * 2000-05-04 2003-12-16 Snaptrack, Incorporated Methods and apparatuses for using mobile GPS receivers to synchronize basestations in cellular networks
US7680461B2 (en) 2003-11-05 2010-03-16 Sony Corporation Wireless communications system, wireless communications method, and wireless communications apparatus
JP2005184730A (en) 2003-12-24 2005-07-07 Sony Corp Radio communication system, radio communication apparatus, and radio communication method, as well as computer program
JP4474934B2 (en) 2004-02-18 2010-06-09 ソニー株式会社 Wireless communication system, wireless communication apparatus, wireless communication method, and computer program
JP4604545B2 (en) 2004-05-10 2011-01-05 ソニー株式会社 Wireless communication system, wireless communication apparatus, and wireless communication method
JP4543737B2 (en) 2004-05-10 2010-09-15 ソニー株式会社 Wireless communication system, wireless communication apparatus, wireless communication method, and computer program
JP4604798B2 (en) 2004-05-10 2011-01-05 ソニー株式会社 Wireless communication system, wireless communication apparatus, wireless communication method, and computer program
JP2006246202A (en) * 2005-03-04 2006-09-14 Nec Corp Optimal intermediary node selecting method, and node and multihop radio communication network system
JP4292419B2 (en) * 2005-07-25 2009-07-08 ソニー株式会社 Monitor terminal
JP2008072251A (en) * 2006-09-12 2008-03-27 Canon Inc Communication apparatus and its control method and program, and storage medium
JP4818066B2 (en) * 2006-10-23 2011-11-16 パナソニック株式会社 Wireless meter reading system and wireless meter reading method
CN100548071C (en) 2007-09-18 2009-10-07 北京邮电大学 Multi-frequency point TD-SCDMA group network and realization of Communication method based on relaying technique
JP2009094692A (en) * 2007-10-05 2009-04-30 Yamaha Corp Wireless communication system, wireless controller, wireless communication terminal
JP2009093406A (en) 2007-10-09 2009-04-30 Fuji Xerox Co Ltd Print information processor, printing system, and program
JP5038924B2 (en) 2008-01-25 2012-10-03 株式会社エヌ・ティ・ティ・ドコモ Relay transmission system, base station, relay station and method
EP2327172B1 (en) * 2008-09-05 2018-11-07 Telefonaktiebolaget LM Ericsson (publ) Methods and arrangements in a radio access network
EP2374225B1 (en) * 2008-11-18 2018-01-10 Telefonaktiebolaget LM Ericsson (publ) Methods and arrangements for determining radio characteristics of a radio link
US8446856B2 (en) * 2008-12-19 2013-05-21 Research In Motion Limited System and method for relay node selection
US9408161B2 (en) * 2009-02-13 2016-08-02 Telefonaktiebolaget Lm Ericsson (Publ) Controlling energy consumption of a wireless network node
JP5540592B2 (en) * 2009-07-23 2014-07-02 ソニー株式会社 COMMUNICATION SYSTEM, COMMUNICATION CONTROL METHOD, MOBILE TERMINAL, AND RELAY DEVICE
JP5909843B2 (en) 2009-08-10 2016-04-27 ソニー株式会社 COMMUNICATION SYSTEM, COMMUNICATION DEVICE, COMMUNICATION METHOD, AND COMPUTER PROGRAM
JP2011066874A (en) 2009-08-17 2011-03-31 Sony Corp Communication system, communication apparatus, communication method, and computer program
JP2011071963A (en) 2009-08-26 2011-04-07 Sony Corp Communication system, apparatus and method and computer program

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1263396A (en) * 1999-02-03 2000-08-16 松下电器产业株式会社 Radio communication system
CN1902868A (en) * 2003-12-30 2007-01-24 艾利森电话股份有限公司 Method and system for wireless communication networks using cooperative relaying
CN1918860A (en) * 2004-02-06 2007-02-21 皇家飞利浦电子股份有限公司 A system and method for hibernation mode for beaconing devices
JP2006254155A (en) * 2005-03-11 2006-09-21 Kddi Corp Communications apparatus and connection method to base station by multi-hopping
JP2008235962A (en) * 2007-03-16 2008-10-02 Fujitsu General Ltd Radio communication system
WO2008149598A1 (en) * 2007-06-04 2008-12-11 Sony Corporation Communication system, communication device, communication method, and computer program
JP2009159409A (en) * 2007-12-27 2009-07-16 Kyocera Corp Radio communication system, mobile station, and radio communication method

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